Conventionally, a shade is raised or lowered by pulling a lift cord. The lift cord is disposed externally of the shade. Thus, it is possible that the lift cord may tie children's necks for playing. This is very dangerous since the child may be hung accidentally. As such, the lift cord is typically concealed in a lifting mechanism in a lowest slat for safety reason.
FIG. 1 shows a window shade B incorporated a lifting mechanism A disclosed in U.S. Pat. No. 6,024,154. The lifting mechanism A is comprised of many components. As such, its components are mounted in a lower slat B1. This inevitably increases the size of the lower slat B1. Moreover, it increases the manufacturing cost, the weight of the lower slat B1, and winding force exerted on spring means of the lifting mechanism A, resulting in shortening the useful life of the shade. Thus, the need for improvement still exists.